LazySpec

Automatically generate minimal spec files for Javascript modules. Works well with Jest snapshots to make painless tests. For example, given a test file src/components/Button.jsx,

import React from 'react';

class Button extends React.Component {
  static propTypes = {
    level: React.PropTypes.oneOf([
      'primary', 'secondary', 'tertiary', 'quaternary', 'text', 'icon',
    ]),
    disabled: React.PropTypes.bool,
    label: React.PropTypes.string.isRequired,
    height: React.PropTypes.number,
    children: React.PropTypes.element.isRequired,
  };

  render() {
    return (
      <button disabled={this.props.disabled}>
        <b>{this.props.label}</b>
      </button>
    );
  }
}

export default Button;

it will generate src/components/__tests__/Button-test.js:

/* @lazyspec (remove to manage manually) */
/* eslint-disable */
import Button from '../Button.js';

import React from 'react';
import renderer from 'react-test-renderer';

describe('Button', () => {
  it('exists', () => {
    expect(Button).toBeTruthy();
  });

  it('renders', () => {
    const comp = <Button children="mockElement" label="mockString" />;
    const tree = renderer.create(comp).toJSON();
    expect(tree).toMatchSnapshot();
  });
});

Usage

npm install -g lazyspec
lazyspec path/to/fileOrDir

For every dir in the list, it will glob all the .js and .jsx .js and add them.

For each file, it will generate a spec and the __tests__ dir if necessary. So far it only supports the Jest style layout but PRs for other test runners and layouts are welcomed!

In dev you can do, ./src/cli.js path/to/fileOrDir.

Known Issues

• Required props of functional stateless components aren't detected

• Custom proptypes are never interpreted as required (e.g. message: MessageInterfacePropType.isRequired)

• Fails when more than one component is exported from a module. react-docgen now has findAllExportedComponentDefinitions, but we don't use it because modules often export a HOC and its base component so it would be redundant. Eventually this tool could detect which is the HOC and omit it.